Inbuilt artisteer header slider not responsive?

I just saw that the artisteer inbuilt wordpress header slider isn't responsive...it seems to work for the width but not the height...and the slider content (pic) doesn't get resized proportionally with all the rest of the design. Any advice to avoid this?

That's true that Artisteer header sliders are not fully responsive.
You can use the workaround provided by Tanya in the forum thread mentioned in the second message or use this code:
.responsive .art-slide-item {
background-size: 100% 100%!important;
}